Most premature morbidity and mortality from cancer is preventable through primary prevention involving interventions to reduce cancer risks or secondary prevention involving early detection and treatment of localized disease. Despite the clear need for cancer prevention research training, there has been very little support for such programs. For the last 19 years, the USC training program in cancer epidemiology and control has been one of a very small number of T32 programs contributing to the nation's pool of qualified researchers in cancer prevention and control. To date, we have trained 39 postdoctoral fellows and 16 predoctoral trainees, all but two with active careers in cancer-related research and/or teaching. This proposal requests continued support for a cancer control and epidemiology research-training program at USC, where program and collaborating clinical and public health faculty are nationally and internationally recognized for their research in cancer epidemiology/etiology, primary prevention, early detection, and treatment compliance. The successful record of extramural funding and collaborative investigations of USC cancer control faculty coupled with the resources of the USC-Norris Cancer Center, provide an exceptionally rich training environment. Program resources interlocking relationships and shared faculty appointments with the L. A. County Dept. of Health Services;the China CDC's;a Transdisciplinary Tobacco Use Research Center;an Environmental Health Sciences Research Center, and a Transdisciplinary Drug Prevention Research Center, all NIH-funded;a SEER-funded Cancer Surveillance Program;the Zilkha Neurogenetic Institute;a major childhood obesity research program;private hospitals and medical centers;international, national and regional databases;outstanding computer, IT, and statistical resources;and association with community organizations, school districts, work sites, and health departments throughout the United States, the Pacific Rim, and South America. Funds are requested for five predoctoral and four postdoctoral trainees. Postdoctoral positions are allocated to behavior and Epidemiology research training emphasizing collaborative studies;one newly requested position is allocated to statistical genetics research bridging epidemiology and cancer risk behavior. The postdoctoral program requires course work or the equivalent in the biological basis of cancer, cancer epidemiology, and statistical methods. Emphasis is placed on involving fellows in ongoing research projects, and assisting them in developing their own research programs. Predoctoral trainees receive the PhD degree in Health Behavior Research (HBR) and are selected from among the most promising upper level HBR graduate students in the department. Predoctoral training includes structured course work and all trainees attend weekly research seminars, directed research, weekly research team meetings, and writing groups. All trainees must attend a mini-course on research ethics. Minority recruitment plans are described.